DIY two Leslie 110's

[Guest]

Your thoughts and advice, if you please, on a no-budget leslie conversion for my M3.</p>

I'm considering converting one of my Leslie 110's by replacing the speaker with a tweeter or even stationary tweeter&amp;horn, directed down into the rotating foam drum.  I would split the signal with a crossover, feeding bottom to one leslie, high end to the DIY leslie.  Currently (no pun intended), I am using a dynaco monoblock as amp.  Would prefer to split post-amp, but before is also a possibility as I have a few nice old amps around.  I want to keep this very low budget, otherwise I'd just go buy the horns/driver/motor or a different leslie!  Thoughts on what a horn thru rotating foam drum would sound like?  For recording only.  I reckon I could figure out a way to control speeds, or even have separate speed controls for each leslie.  My current method on/off/on is a crude homeDIY type made by the former owner.  Anyone ever tried something like this?  Anyone smart ever tried something like this?</p>

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[CEB]

Re: DIY two Leslie 110's



Try and see if it works but off the top of my head I don't think iit would work well for 2 reasons.</P>


1) High end throws a lot differently than low end.I don't think the high end driverwould project out the drum becuase the sound waves would be blocked. </P>


2) Thefoam would act as an acoustic insulaltor further cutting down the sound.</P>


But I am no expert you could give it try and see what happens.</P>

[Guest]

Re: DIY two Leslie 110's



Thanks. I have to agree with you.</p>

So tweeter/foam drum is a bad idea.  Is there a cheap way to replace the drum with a DIY driver/bearing/rotating horn?  The cost of an original driver is far too much for me for an experiment.  Thoughts on good-sounding drivers?</p>

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[CEB]

Re: DIY two Leslie 110's



You could try something like this but you would have to rig up some kind of adapter plate because the driver has a 1.75" throat.</P>


http://www.mcmelectronics.com/produc...LAID=220571046</P>
<P mce_keep="true"></P>


Look at cheap Public Address drivers. Thekind used for commerical outdoor usuage That is what you want. That is pretty much what the Jensen V-21 was. [:D] You may be able to find a cheap PA driver with a smaller throat size.</P>


Good high freq. drivers sound crappy because they reproduce sounds you don't want too hear. </P>


Cheap is good</P>
<P mce_keep="true"></P>

[back52887]

Re: DIY two Leslie 110's



Many early built-in leslies, and the model 25 had wooden rotors, rather than foam. If you could get hold of one of them, you would aliviate your concerns over high frequency absorbtion.[:-*]</P>


Lee</P>

[Brendon Wright]

Re: DIY two Leslie 110's



G'day leslie DIY bloke!</P>


I've made a two part leslie with spinet internal leslies, the high freq (aye, foam) rotor, and to boot, it has a solid stateampedT-500 playing through it, but I've spent the past 6 months moddingthe organfor fun. It sounds grand.</P>


I've also got info on changing the motor direction of one set of motors, the upper and lower go in opposite directions.</P>


I've spent a bit of time sorting out crossovers etc. The high freq rotor will need a midrange driver as well, a tweeter won't go down as low as 800Hz, and it'll go above 8000Hz, so a high range cutcould be useful too, it's all easy peasy (especially when someone else has got results to feed you to try out!) AND progressive, each step sounds great, but is improved by the next step.</P>


Here's the last recording of my own project for your own information. I've since altered the crossover and favoured the lower rotor more, because I wasn't getting the swirl between high and low rotors that was necessary, the next "pulp" recording will show the improvement.</P>


but for now, have a listento this and you'll see your project will be worth pursuing with a capital P...</P>


(I'd also recommend stacking the cabinets, cos treble at ear height is by far the best!)</P>


http://furfsw.bay.livefilestore.com/...s.mp3?download</P>


I found theleslie at this point was too crisp... so loss of frequency is of little issue!</P>


Cheers!</P>


-Brendon</P>

[Brendon Wright]

Re: DIY two Leslie 110's



PS. I'm not someone clever, but have been given lots of good advice.</P>


I've also got a switch set up like a halfmoon which switches both units at the same time. I'll pass on the info when you need it, but I'd better start work for the day right now....</P>


Cheers!</P>


-Brendon</P>

[Brendon Wright]

Re: DIY two Leslie 110's



I just realised the clip posted up doesn't show theleslie ontremelo very much, and chorale is hard to pic because of the tones used and the positioning of the mic. These following two show better examples, but were earlier in the DIY project still. Well before the crossover was sorted out. The recordings are all through laptop onboard mic.</P>


http://furfsw.bay.livefilestore.com/...s.mp3?download</P>


The above also has a demoof a simple zener diode overdrive which showcases the chorale really well.</P>


http://furfsw.bay.livefilestore.com/...s.mp3?download</P>


-B</P>

[Brendon Wright]

Re: DIY two Leslie 110's

[quote user="Brendon Wright"]


the high freq (aye, foam) rotor, and to boot, it has a solid stateampedT-500 playing through it, [/quote]</P>


Hmm... I sense a thought lost in mid sentence here. My apologies. No Idea what it was.</P>

[bossbandbob]

Re: DIY two Leslie 110's



I agree with Brendon, I have watched &amp; heard his in the making
(on the "Building Your own Leslie" and "Removing Built in Leslie"
threads here) and I have also made a DIY top rotor Leslie for my 130
but pretty much from scratch. I think it sounds pretty decent. People
also told me that my idea "couldn't be done."</p>

If you have
the proper crossovers and will amp the top unit with adjustable tone
&amp; volume controls it should work through your present rotor. I had
also previously made my 130's stationary tweeter and woofer into a
dual coax by firing both into the rotor. I also tried that with a
midrange which had a better effect than the tweeter but both were a bit
overwhelmed by the lower frequencies swriling through the same rotor at
the same time. The higher frequencies were still evident however. With
2 seperate units you won't have that problem.

</p>

You will absolutely need the midrange. On my DIY top rotor I
eventually dropped my tweeter altogether in favor of a midrange. You
will also have to adapt the size of your speaker(s) to the opening to
the 110's rotor which you could do with a piece of plywood with
the proper size holes cut in it to fit your speakers.</p>

B</p>

[bossbandbob]

Re: DIY two Leslie 110's



Here's the thread and Skippy's DIY top rotor that started it all.
You'll also find info pictures and sound clips on Brendon's, Jeff's and
my DIY leslie's</p>

http://organforum.com/forums/29/75064/ShowThread.aspx</p>

Be careful though-it is (yikes!) up to 29 pages now!</p>

.......It's all Brendon's fault : )</p>

Bob</p>

[Guest]

Re: DIY two Leslie 110's

Thanks for pointing me in the right direction everyone.

[Brendon Wright]

Re: DIY two Leslie 110's

What ideas have you got forming for your 110s?

[Guest]

Re: DIY two Leslie 110's



The story so far:</p>

I've nixed the idea of using two cabinets, and instead I am just modifying one. I acquired a hammond treble horn(s). I plan on subdividing the cabinet (but leaving one side of the horn area open, since the width of the rotating horns is greater the width of the cabinet.) I'll have to router some vents into the cab. I'm going to have the 2speed motor pull the foam drum and also a 2nd belt. This long belt runs through a pulley, up to the horn level, pulley, around the horns and back down the same way. So the horns will rotate opposite to the drum. I might put a gear-type loop in the system, so that I can change the horn's rpm by varying the size of wheel I use. The pulleys I have are from a sliding glass door. They are too loud. As a driver I'm going to try an old TOA paging PA system horn I have laying around. Not sure what the freq response on it is, but probably not hi-fi, which I want to avoid. Any thoughts on:</p>

-using the PA horn? </p>

-Will subdividing the cab make the 12" spkr's area too small and change the sound?</p>

-Any reason NOT to mount the horns on the exterior top of the cabinet? If I do this they'll be surrounded by a safety grill. The leslie is going to be for recording only, not for gigging.</p>

- supercheap pulleys?</p>

- Is there a way to avoid a crossover, perhaps by running the speaker and driver off the same amplifier but cutting the lows from the horn and highs from the speaker? And is it necessary to cut the highs from the speaker?</p>

By the way, Brendon your mp3's/stuff sounds really great! You obviously know what you're talking about! </p>

[Brendon Wright]

Re: DIY two Leslie 110's



Buzz</p>

Wow,you're really gettin' inventing!</p>

The cavity size IS fairly vital to bass production, so it would probably be better not to subdivide, I think. You could of course grab the motor from a cheap late 70's japanese Hammond organ's internal leslie... and build a small enclosure to sit on top of the 110, this would still look tidy.</p>

These organs turn up a lot in the community paper classifieds for less than US$20, or for free. They often sounded so cheesy that folks just want to get rid of them now.</p>

The PA horn is worth a crack, I'm looking into the same sort of thing at the moment cos I'm sick of my midrange speakers crackling. Crossovers are easy to build. You may even find the bits inside an old 2 or 3 way stereo speaker at the dump!</p>

If you want advice, I've been doing a bit of tinkering on that respect. In order to protect your treble speaker from the bass it CAN be as simple as a single capacitor before the speaker.</p>

I'd better get back to work though....</p>

Cheers</p>

-Brendon</p>

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